bug#11390: 24.1.50; Emacs on OSX -- strange artifacts in the buffer

From:

Eugene Dedits

Subject:

bug#11390: 24.1.50; Emacs on OSX -- strange artifacts in the buffer

Date:

Tue, 1 May 2012 15:16:07 -0400

This bug report will be sent to the Bug-GNU-Emacs mailing list
and the GNU bug tracker at debbugs.gnu.org. Please check that
the From: line contains a valid email address. After a delay of up
to one day, you should receive an acknowledgement at that address.
Please write in English if possible, as the Emacs maintainers
usually do not have translators for other languages.
Please describe exactly what actions triggered the bug, and
the precise symptoms of the bug. If you can, give a recipe
starting from `emacs -Q':
If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
`bt full' and `xbacktrace'.
For information about debugging Emacs, please read the file
/Applications/Emacs.app/Contents/Resources/etc/DEBUG.
In GNU Emacs 24.1.50.2 (x86_64-apple-darwin10.8.0, NS apple-appkit-1038.36)
of 2012-05-01 on pde
Windowing system distributor `Apple', version 10.3.1038
Configured using:
`configure '--with-ns' '--prefix=/Users/eugene/tmp/emacs/build''
----------------------------------------------------------------------------------------
Attached screenshot shows strange artifacts that appear *some times* when I
-- scroll buffer with the mouse wheel
-- switch to some other application and back
These artifacts disappear if I
-- select region
-- increase\decrease font size
-- move cursor over those positions
This seems to be independent of the major mode.
If I use smaller font size (Monaco 10pt, no antialiasing) this never happens.
For any bigger
font size (Monaco 12pt and up, antialiased) these artifacts show up.
I was able to reproduce it using
-- my own build of emacs 24.1.50
-- latest pre-builds found on EmacsForOSX
-- latest Aquamacs
------------------------------------------------------------------------------------------
Thanks,
Eugene.
________________________________
Change is in the Air - Smoking in Designated Areas Only in
effect.<http://www.csi.cuny.edu/tobaccofree>
Tobacco-Free Campus as of July 1, 2012.